The optics of photography and photographic lenses (1904)
Taylor, J. Traill (John Traill), 1827-1895, Everitt, P. F · London ; New York : Whittaker & Co. · leaf 33
DIAPHRAGMS OR STOPS. 21 cures all the evils arising from spherical aberration by debarring access to those rays which, if transmitted, would interfere with ultimate sharpness. In Fig. n we show in what manner the ‘curative5 … powers of the diaphragm are exercised when employed as a stop to obstructant rays, both central and oblique. Observe what havoc would be played as regards focal sharpness if the mass of the rays were permitted indis- criminate access to the lens. The dotted lines represent those by which definition…
Photographic optics · Photographic lenses
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